Does intracoronary ultrasound (ICUS) provide reliable and reproducible measurements of atherosclerotic plaque dimensions?
Intracoronary ultrasound demonstrates low inter- and intraobserver variability for measuring atherosclerotic plaque, suggesting it is a reliable tool for regression trials.
BACKGROUND AND HYPOTHESIS: Serial coronary angiography cannot reliably detect the small changes in arterial dimensions. Measurement of arterial dimensions by intracoronary ultrasound (ICUS) may be a superior method to determine the extent of atherosclerotic burden since it directly images the diseased portion of the vessel. METHODS: To quantify inter- and intraobserver variability of ICUS measurements, 27 images of atherosclerotic coronary lesions were measured by two study physicians and repeated 14 days later. RESULTS: Interobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.96, 0.99, and 0.91, respectively. Intraobserver correlation coefficients for external elastic lamina, lumen, and effective plaque area were 0.99, 0.99, and 0.97, respectively. To determine progression or regression in effective plaque area, a minimal difference of 2.77 mm2 (which represents a 23% change in plaque area) is needed. CONCLUSIONS: Direct visualization of the extent of atherosclerosis by ICUS can be accomplished with a low degree of inter- and intraobserver variability. ICUS may be a preferable alternative to angiography in atherosclerosis regression trials.
Foster et al. (Wed,) studied this question.